While major seizures are rare in the city centre, garda crime statistics indicate the supply of drugs into the area is much more concentrated than anywhere else in Ireland.

In fact, the Store Street and Pearse Street sub-districts, which police areas either side of the River Liffey, account for the same amount of recorded drug crime as the next 12 worst areas in Dublin combined.

The data makes grim reading for tourism bodies and will reinforce perceptions that the capital's centre is blighted by the scourge of drug use.

The drug blackspot statistics also reveal problem areas outside the capital, with the Bray sub-district in Co Wicklow and Galway city among the worst affected per head of population.

The data, detailing drug offences for the first six months of the year, was supplied by gardai to the Central Statistics Office.

It covers crimes such as the importation, cultivation or manufacture of drugs, possession of drugs for sale or supply, possession of drugs for personal use, the forging or altering of prescriptions, or obstruction of a garda contrary to the Misuse of Drugs Act.

The Store Street sub-district accounted for 994 drugs offences per 100,000 people, while the Pearse Street sub-district had a rate of 756 drug offences per 100,000 people.

Both areas also topped the table when it came to theft crimes, indicating a direct link between drug offences and elevated levels of theft, such as pickpocketing, bag snatching and breaking into cars.

In comparison, the third worst area for drug offences in Ireland, the north Tipperary garda sub-district Ballingarry North, had a rate which was less than a third of that recorded in Store Street.

Population

Ballingarry North's position in the league table owes more to its low population - 692 people according to the 2011 census - than the rate of offences, as there were just two recorded there between January and June of this year.

However, other areas in the top ten worst affected have considerably larger populations.

The fourth most affected area was Bray, with 240 offences per 100,000 people, roughly a quarter of the rate experienced in Store Street.

Galway city held fifth place, with a rate of 208 drug offences per 100,000 people.

Within Dublin, the worst affected area outside of the city centre was Ronanstown, with a rate of 185 drugs offences per 100,000 people.

It was followed by Kevin Street (179 per 100,000), Finglas (173 per 100,000), Ballyfermot (167 per 100,000) and Mountjoy (144 per 100,000).

Two areas in Dublin, Garristown and Skerries, did not have any recorded drug crime at all in the first six months of the year.

On a county-by-county basis, Roscommon, Mayo, Meath and Leitrim had the lowest rates of drug crime.